A multi-frequency internal antenna apparatus (10) for a clamshell type electronic device includes a flexible circuit (20) that electrically couples circuitry between the main housing (12) and flip housing (14). A conductive element (36) is disposed on the main housing (12) and tuned to be electrically resonant above the operating frequencies of the electronic device. The conductive element (36) is disposed in proximity to the flip housing (14) in the open position and is electrically coupled at a high impedance point to the flexible circuit (20) and subsequently to the circuitry in the flip housing. When the movable flip housing is in the open position and being held by a user, the circuitry in the movable flip housing forms a secondary conductive element providing dipole characteristics that tunes the combined conductive elements to the operating frequencies of the electronic device.